Differentiation potential of human CD8⁺ T-cell subsets following cytokine or TCR stimulation. (A) CD8⁺ T-cell subsets isolated by cell sorting were labeled with CFSE and stimulated with allogeneic mDCs or with IL-7 and IL-15. After 7 days cells that performed the same number of divisions were analyzed for the expression of CD45RA and CCR7. One representative experiment of 4 is shown. (B) Purified CD8⁺ naive and T_CM cells were either analyzed for the expression of perforin and CD45RA ex vivo or labeled with CFSE, stimulated with allogeneic mDCs or with IL-7 and IL-15, and analyzed after 7 days for CD45RA and perforin expression. One representative experiment of 3 is shown. (C) Purified CFSE-labeled CD45RA–CD8⁺ T_CM cells were stimulated in medium containing 10³ U/mL IL-2, 25 or 2.5 ng/mL (1:10) IL-7 and IL-15 in the absence or presence of 10 ng/mL IL-6 and IL-10 in either uncoated (thick line) or anti-CD3–coated wells (dotted line). Viable dividing cells were analyzed on day 7 for CD45RA expression. Bars indicate positive staining and numbers percentage of CD45RA⁺ cells in the absence (bold) or presence (nonbold) of anti-CD3 antibody.